Author's sums don't seem to make sense.
How could an increase in $5 per hour for minimum wage translate into $40,000 per employee? Worst case scenario:
260 days * 8 hours * $5 increase = $10,400
How could an increase in $5 per hour for minimum wage translate into $40,000 per employee? Worst case scenario:
260 days * 8 hours * $5 increase = $10,400
Some garment tasks inherently taking a lot of space to lay out cloth for cutting or sewing imply garment companies are paying maybe twice as much for a garment worker's space than for a software dev's space, an extremely large multiple of employee income is paid in rent, and moving away from CA would result in enormous savings in rent.
Clearly moving production anywhere other than CA would save an enormous about of money in rent. In rural nowhere you can get industrial zoned buildings for about $4/sq/yr or about 500 times less than CA office space, at which point you have to start looking in more detail at costs of utilities and other expenses that were noise at higher rents but are now significant relative to the cheaper rent.